That our brains account for 20 percent of our calorie use tends to amaze people, as it did me. Now it appears that about a third of that is devoted to brain maintenance rather than electrical signaling. The full dish here:

It is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body’s total haul. Until now, most scientists believed that it used the bulk of that energy to fuel electrical impulses that neurons employ to communicate with one another. Turns out, though, that is only part of the story.

A new study in Proceedings of the National Academy of Sciences USA indicates that two thirds of the brain’s energy budget is used to help neurons or nerve cells “fire” or send signals. The remaining third, however, is used for what study co-author Wei Chen, a radiologist at the University of Minnesota Medical School, refers to as “housekeeping,” or cell-health maintenance.